US20100254145A1 - Lighting device - Google Patents
Lighting device Download PDFInfo
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- US20100254145A1 US20100254145A1 US12/753,307 US75330710A US2010254145A1 US 20100254145 A1 US20100254145 A1 US 20100254145A1 US 75330710 A US75330710 A US 75330710A US 2010254145 A1 US2010254145 A1 US 2010254145A1
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- light
- exit surface
- light exit
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- 239000000758 substrate Substances 0.000 claims abstract description 18
- 230000007423 decrease Effects 0.000 claims abstract description 6
- 229920005989 resin Polymers 0.000 claims description 13
- 239000011347 resin Substances 0.000 claims description 13
- 239000004973 liquid crystal related substance Substances 0.000 description 10
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 7
- 238000005286 illumination Methods 0.000 description 6
- 230000020169 heat generation Effects 0.000 description 2
- 239000012788 optical film Substances 0.000 description 2
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 239000004925 Acrylic resin Substances 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
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- 239000010408 film Substances 0.000 description 1
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- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920002050 silicone resin Polymers 0.000 description 1
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- 239000004945 silicone rubber Substances 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/48—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by the semiconductor body packages
- H01L33/52—Encapsulations
- H01L33/54—Encapsulations having a particular shape
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B19/00—Condensers, e.g. light collectors or similar non-imaging optics
- G02B19/0004—Condensers, e.g. light collectors or similar non-imaging optics characterised by the optical means employed
- G02B19/0009—Condensers, e.g. light collectors or similar non-imaging optics characterised by the optical means employed having refractive surfaces only
- G02B19/0014—Condensers, e.g. light collectors or similar non-imaging optics characterised by the optical means employed having refractive surfaces only at least one surface having optical power
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B19/00—Condensers, e.g. light collectors or similar non-imaging optics
- G02B19/0033—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use
- G02B19/0047—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use for use with a light source
- G02B19/0061—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use for use with a light source the light source comprising a LED
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/1336—Illuminating devices
- G02F1/133602—Direct backlight
- G02F1/133603—Direct backlight with LEDs
Definitions
- the present invention relates to a lighting device to be used suitably in, for example, a backlight of a liquid crystal display.
- LEDs have replaced conventional fluorescent tubes as dominant light sources for backlights of small and medium-sized liquid crystal displays, and further are gaining widespread use as light sources for large-screen liquid crystal displays or for general illumination.
- edge light type backlights In large-screen liquid crystal displays like liquid crystal TVs, direct type backlights have been used widely instead of edge light type backlights, which are commonly used in small and medium-sized liquid crystal displays. This is because such edge light type backlights have the following disadvantages.
- An edge light type backlight is configured such that a light source is disposed at a lateral side of a light guide plate and optical films such as a prism sheet and a diffusing sheet further are disposed on the light emission side of the light guide plate.
- This configuration enables a reduction in the thickness of a display.
- the required light quantity as well as the area of the display increase quadratically.
- the length of the lateral side, on which the light source can be disposed increases linearly. As the screen size increases, the required light quantity density increases, which makes it more difficult to position the light source, and the heat generation density also increases, which makes it more difficult to dissipate the heat.
- a direct type backlight is configured such that a large number of light sources are disposed in a plane beneath a liquid crystal panel and a diffusing plate and optical films such as a prism sheet and a diffusing film are disposed between the light sources and the liquid crystal panel, the required light quantity density does not change even when the screen size increases. Therefore, the heat generation density also remains unchanged, which is suitable for large screens.
- A is a constant that depends on the distance from the light source to the illuminated surface.
- a LED light source includes a LED element mounted on a substrate and a transparent resin that encapsulates the LED element. That is, the transparent resin forms a lens.
- the encapsulating resin is formed in a hemispherical shape having its center at the LED element, the light emitted therefrom exhibits substantially Lambertian distribution.
- the Lambertian distribution is a light distribution characteristic such that a light ray emitted in the optical axis direction has the highest intensity K0 and a light ray emitted in a direction at an angle of ⁇ with respect to the optical axis has a relative emission intensity K( ⁇ )/K0 of Cos( ⁇ ).
- FIG. 3 shows the relative illuminance distribution
- the illuminance on the illuminated surface decreases sharply with increasing angle.
- the angle ⁇ of light emitted to a position on the surface with a distance x from the optical axis is represented by the following equation:
- the resulting graph indicates the spatial illuminance distribution, in which the position on the optical axis is brightest and becomes darker suddenly with increasing distance from the optical axis.
- the LED light sources used for a direct type backlight are required to have a characteristic of illuminating a largest possible area uniformly with a smallest possible number of LED light sources, the characteristic as mentioned above is not desirable for such a backlight.
- the characteristic of illuminating a specific area uniformly may be effective for use in, for example, a desk lamp, etc., in addition to a backlight.
- Equation 1 The condition for illuminating a flat surface uniformly using a single point light source is that the right-hand side of Equation 1 has a constant value L0 irrespective of the angle ⁇ , that is, the following equation is satisfied.
- L0/A is the light intensity at the angle ⁇ of 0 degree, that is, the axial light intensity.
- the light distribution characteristic for achieving a uniform illuminance distribution is obtained when the relative light intensity distribution K( ⁇ )/K0 normalized with respect to the axial light intensity K0 satisfies following equation:
- FIG. 4 shows the emitted light intensity distribution
- JP 2006-092983 A discloses a shape of an encapsulating resin having a concave around the optical axis and a convex extending outwardly from the concave.
- the lighting device of the present invention includes: a substrate; a LED element mounted on the substrate; and a lens disposed on the substrate so as to cover the LED element.
- the lens has a light exit surface that is rotationally symmetric with respect to an optical axis.
- the light exit surface includes a first light exit surface that extends from the optical axis, and a second light exit surface that leads from a periphery of the first light exit surface to the substrate, and a curve obtained by cutting the light exit surface by a plane including the optical axis has, on a boundary between the first light exit surface and the second light exit surface, a change point at which a rate of inclination decreases discontinuously.
- An angle between the optical axis and a line segment connecting the change point and a light emission center of the LED element is approximately equal to an emission angle with the highest light intensity, among emission angles that are angles between light rays emitted from the light exit surface and the optical axis, when the light rays are sorted by respective emission angles.
- the “rate of inclination” is a rate of increase in the height of a point on the light exit surface (distance from the substrate to the point) with respect to an increase in the distance of the point from the optical axis.
- the phrase “approximately equal to” means that a difference between the angles is 5 degrees or less.
- the characteristic of increasing the emitted light intensity sharply with increasing light emission angle is obtained, which makes it possible to illuminate a larger area with a nearly uniform illuminance. Therefore, when the lighting device of the present invention is used in a backlight of a liquid crystal display it is expected to contribute to a reduction in the thickness of the display.
- FIG. 1 is a cross-sectional view of a lighting device according to one embodiment of the present invention.
- FIG. 2 is a graph showing the light distribution characteristics of the lighting device of FIG. 1 .
- FIG. 3 is a graph showing the illuminance distribution obtained when a Lambertian light source is used.
- FIG. 4 is a graph showing a condition for illuminating a flat surface with a uniform illuminance by using a single light source.
- FIG. 1 is a cross-sectional view of a lighting device (surface illumination device) according to one embodiment of the present invention.
- This lighting device includes a mounting substrate 1 , a LED element 2 mounted on the mounting substrate 1 , and a lens 4 disposed on the mounting substrate 1 so as to cover the LED element 2 .
- a blue LED chip is used as the LED element 2 .
- a phosphor layer 3 for converting blue light into yellow light is provided around the LED element 2 so as to encompass the LED element 2 from the side opposite to the mounting substrate 1 .
- the LED element 2 and the phosphor layer 3 are encapsulated with transparent resin, and this transparent resin forms a lens 4 .
- the surface of the transparent resin which is to be an interface with air, is molded in a mold into a specific shape so as to form a light exit surface (light distribution control surface) 41 that is rotationally symmetric with respect to the optical axis A.
- the transparent resin include epoxy resin, silicone resin, acrylic resin, and polycarbonate.
- the lens 4 also may be formed of silicone rubber or the like.
- the light exit surface 41 of the lens 4 need not be completely rotationally symmetric, and it may be substantially rotationally symmetric.
- a part of blue light emitted from the LED element (blue LED chip) 2 passes through the phosphor layer 3 and the other part of the light is converted into yellow light by the action of the phosphor. As a result, white light is emitted from the phosphor layer 3 .
- the white light emitted from the phosphor layer 3 enters the lens 4 , is refracted at the light exit surface 41 according to its incident angle with respect to the light exit surface 41 , and then emitted from the light exit surface 41 in a specific direction.
- the shape of the light exit surface 41 is obtained in the following manner. First, a continuous surface represented in a specific functional form is designed so that its light distribution is approximated to a target light distribution, and then the resulting continuous surface is cut by a cylindrical surface having its center on the optical axis A (in FIG. 1 , the shape of the continuous surface to be cut is indicated by double-dashed lines). That is, the light exit surface 41 includes a first light exit surface 41 a that extends from the optical axis A, and a second light exit surface 41 b that leads from the periphery of the first light exit surface 41 a to the mounting substrate 1 along the optical axis direction in which the optical axis A extends.
- the first light exit surface 41 a of the present embodiment has a concave around the optical axis A and a convex that extends outwardly from the concave.
- the second light exit surface 41 b is a cylindrical surface.
- a curve obtained by cutting the light exit surface 41 by a plane including the optical axis A has, on the boundary between the first light exit surface 41 a and the second light exit surface 41 b , a change point P at which a rate of inclination decreases discontinuously.
- the first light exit surface 41 a and the second light exit surface 41 b need not necessarily be connected to each other to form a clear ridge line therebetween.
- the first light exit surface 41 a and the second light exit surface 41 b may be connected to each other to form a sharp curve (for example, a curve with a curvature radius of about 1 mm) therebetween. That is, the rate of inclination from the first light exit surface 41 a to the second light exit surface 41 b has only to decrease substantially discontinuously at the change point P.
- a position where the continuous surface is cut is a point of intersection of the continuous surface and a straight line extending from the light emission center of the LED element 2 at an angle ⁇ cut with respect to the optical axis A.
- the above angle ⁇ cut is determined so that it coincides substantially with the emission angle ⁇ p with the maximum light intensity in the previously designed continuous surface.
- the “emission angle” is each of angles between light rays emitted from the lens 4 and the optical axis A.
- the “emission angle with the maximum light intensity” is an emission angle with the light highest intensity, among emission angles, when light rays emitted from the continuous surface are sorted by respective emission angles.
- an angle between the optical axis A and a line segment connecting the change point P and the light emission center of the LED element 2 becomes equal to the above angle ⁇ cut. Since this angle ⁇ cut is substantially equal to the above angle ⁇ p, the angle ⁇ cut also is approximately equal to the emission angle with the highest light intensity, among emission angles, when light rays emitted from the light exit surface 41 are sorted by respective emission angles.
- FIG. 2 is a graph showing the light distribution characteristics obtained by the previously designed continuous surface shape, and the light distribution characteristics obtained by the final shape formed by cutting the continuous surface by the cylindrical surface, that is, the light distribution characteristics of the lighting device of the present embodiment.
- the horizontal axis indicates the emission angles of light rays emitted from the lighting device
- the vertical axis indicates the relative light intensities obtained by normalizing the intensities of the light rays emitted in these angle directions with respect to the intensity in the optical axis direction.
- the final shape formed by cutting the continuous surface by the cylindrical surface exhibits the following light distribution characteristics, compared with the previously designed continuous surface shape. That is, the peak intensity in the ⁇ p direction increases, and the emitted light intensity also increases sharply with an increase in the emission angle near the angle of ⁇ p. Thus, the resulting curve approaches more closely the curve of the uniform illumination condition of Cos ⁇ 3 ( ⁇ ).
- light rays incident on the cut cylindrical surface are refracted in and around the ⁇ p direction as shown by dotted lines in FIG. 1 , which increases the luminous flux density in and around the ⁇ p direction. That is, light rays having the emission angle of ⁇ p include not only a light ray emitted from the first light exit surface 41 a but also a light ray emitted from the second light exit surface 41 b.
- the second light exit surface 41 b which is a cylindrical surface, is formed by cutting a continuous surface with a cylindrical surface having its center on the optical axis A.
- the effect of increasing the peak light intensity in the ⁇ p direction can be expected as long as the light exit surface 41 has a shape capable of decreasing the rate of inclination discontinuously at a position in or around the ⁇ p direction from the light emission center of the LED element 2 .
- the second light exit surface 41 b may be a tapered surface extending radially toward the mounting substrate 1 .
- the angle with respect to the optical axis A be, for example, 10 degrees or less so that the second light exit surface 41 b leads from the periphery of the first light exit surface 41 a to the mounting substrate 1 along the optical axis direction.
- white light is obtained using a blue LED and a phosphor; but the present invention is not limited to this configuration.
- a white light source by placing LEDs of three primary colors, red, green, and blue, closely to one another near the optical axis and forming a lens to cover these LEDs.
- a white surface light source may be obtained by preparing a plurality of single color light sources, each including a red, green or blue LED and a lens that covers the LED, are placed in a plane so that light rays from the light sources are mixed on a surface to be illuminated.
- Such a configuration makes it possible to obtain easily the characteristic of increasing the emitted light intensity sharply with increasing light emission angle.
- the present invention makes it possible to illuminate a larger area of a target surface almost uniformly. Accordingly, when the present invention is used as a light source for backlights of liquid crystal displays, the thickness of the resulting device can be reduced and uneven illumination also can be reduced.
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- Microelectronics & Electronic Packaging (AREA)
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Abstract
Description
- 1. Field of the Invention
- The present invention relates to a lighting device to be used suitably in, for example, a backlight of a liquid crystal display.
- 2. Description of Related Art
- In recent years, with a remarkably enhanced efficiency and reduced cost of light emitting diodes (LEDs), LEDs have replaced conventional fluorescent tubes as dominant light sources for backlights of small and medium-sized liquid crystal displays, and further are gaining widespread use as light sources for large-screen liquid crystal displays or for general illumination.
- In large-screen liquid crystal displays like liquid crystal TVs, direct type backlights have been used widely instead of edge light type backlights, which are commonly used in small and medium-sized liquid crystal displays. This is because such edge light type backlights have the following disadvantages.
- An edge light type backlight is configured such that a light source is disposed at a lateral side of a light guide plate and optical films such as a prism sheet and a diffusing sheet further are disposed on the light emission side of the light guide plate. This configuration enables a reduction in the thickness of a display. On the other hand, in a large screen display, with an increase in the diagonal screen size, the required light quantity as well as the area of the display increase quadratically. However, the length of the lateral side, on which the light source can be disposed, increases linearly. As the screen size increases, the required light quantity density increases, which makes it more difficult to position the light source, and the heat generation density also increases, which makes it more difficult to dissipate the heat.
- In that respect, since a direct type backlight is configured such that a large number of light sources are disposed in a plane beneath a liquid crystal panel and a diffusing plate and optical films such as a prism sheet and a diffusing film are disposed between the light sources and the liquid crystal panel, the required light quantity density does not change even when the screen size increases. Therefore, the heat generation density also remains unchanged, which is suitable for large screens.
- In the case where an illumination of a flat surface with the above-mentioned direct type backlight or a desk lamp is performed by using approximate point light sources like LED light sources, when an angle from a perpendicular drawn from a light source to a flat surface to be illuminated is θ, and an intensity of light emitted in the θ direction is K(θ), the illuminance L(θ) at a point intersected by the illuminated surface in the θ direction is represented by the following equation:
-
L(θ)=A×K(θ)×Cos3(θ) (Equation 1) - where A is a constant that depends on the distance from the light source to the illuminated surface.
- Generally, a LED light source includes a LED element mounted on a substrate and a transparent resin that encapsulates the LED element. That is, the transparent resin forms a lens. When the encapsulating resin is formed in a hemispherical shape having its center at the LED element, the light emitted therefrom exhibits substantially Lambertian distribution. The Lambertian distribution is a light distribution characteristic such that a light ray emitted in the optical axis direction has the highest intensity K0 and a light ray emitted in a direction at an angle of θ with respect to the optical axis has a relative emission intensity K(θ)/K0 of Cos(θ).
- When a flat surface is illuminated using such a Lambertian light source, the illuminance on the surface is represented by the following equation by substituting K(θ)=K0×Cos(θ) in Equation (1):
-
L(θ)=A×K0×Cos4(θ) - Here, since the illuminance L0 in the optical axis direction is A×K0, the relative illuminance distribution L(θ)/L0 normalized with respect to the illuminance L0 in the optical axis direction is represented by the following equation:
-
L(θ)/L0=Cos4(θ) -
FIG. 3 shows the relative illuminance distribution. - As shown in
FIG. 3 , the illuminance on the illuminated surface decreases sharply with increasing angle. Here, when the distance from the light source to the illuminated surface is D, the angle θ of light emitted to a position on the surface with a distance x from the optical axis is represented by the following equation: -
Tan(θ)=x/D - Accordingly, if the horizontal axis of the graph of
FIG. 3 is redefined as the distance x=D×Tan(θ), the resulting graph indicates the spatial illuminance distribution, in which the position on the optical axis is brightest and becomes darker suddenly with increasing distance from the optical axis. - Since the LED light sources used for a direct type backlight are required to have a characteristic of illuminating a largest possible area uniformly with a smallest possible number of LED light sources, the characteristic as mentioned above is not desirable for such a backlight. The characteristic of illuminating a specific area uniformly may be effective for use in, for example, a desk lamp, etc., in addition to a backlight.
- The condition for illuminating a flat surface uniformly using a single point light source is that the right-hand side of
Equation 1 has a constant value L0 irrespective of the angle θ, that is, the following equation is satisfied. -
A×K(θ)×Cos3(θ)=L0 - By transforming the above equation, the following equation is obtained:
-
K(θ)=L0/A×Cos−3(θ) - In the above equation, L0/A is the light intensity at the angle θ of 0 degree, that is, the axial light intensity. The light distribution characteristic for achieving a uniform illuminance distribution is obtained when the relative light intensity distribution K(θ)/K0 normalized with respect to the axial light intensity K0 satisfies following equation:
-
K(θ)/K0=Cos−3(θ) Equation (2) -
FIG. 4 shows the emitted light intensity distribution. - As is clear from
FIG. 4 , the light intensity required for the uniform illumination increases sharply with increasing angle. Therefore, it is impossible to satisfy theabove Equation 2 in the entire range of angles from −90 degrees to +90 degrees, and thus the goal is to obtain the characteristic similar to the characteristic represented byEquation 2 in as wide a range as possible. - For this goal, various shapes of encapsulating transparent resins have been proposed to improve the light distribution characteristics by utilizing the refraction and reflection at the surfaces of the encapsulating transparent resins. For example, JP 2006-092983 A discloses a shape of an encapsulating resin having a concave around the optical axis and a convex extending outwardly from the concave.
- It is, however, not easy to obtain the characteristic of increasing the emitted light intensity sharply with increasing angle as shown in
FIG. 4 . In particular, the difficulty of obtaining the above-mentioned characteristic increases further if a LED of limited size and an encapsulating resin of limited size are used. - In view of the above problems, it is an object of the present invention to provide a lighting device capable of achieving the characteristic of increasing the emitted light intensity sharply with increasing light emission angle in a simple way.
- In order to solve the above-mentioned problems, the lighting device of the present invention includes: a substrate; a LED element mounted on the substrate; and a lens disposed on the substrate so as to cover the LED element. The lens has a light exit surface that is rotationally symmetric with respect to an optical axis. In this lighting device, the light exit surface includes a first light exit surface that extends from the optical axis, and a second light exit surface that leads from a periphery of the first light exit surface to the substrate, and a curve obtained by cutting the light exit surface by a plane including the optical axis has, on a boundary between the first light exit surface and the second light exit surface, a change point at which a rate of inclination decreases discontinuously. An angle between the optical axis and a line segment connecting the change point and a light emission center of the LED element is approximately equal to an emission angle with the highest light intensity, among emission angles that are angles between light rays emitted from the light exit surface and the optical axis, when the light rays are sorted by respective emission angles.
- As stated herein, the “rate of inclination” is a rate of increase in the height of a point on the light exit surface (distance from the substrate to the point) with respect to an increase in the distance of the point from the optical axis. The phrase “approximately equal to” means that a difference between the angles is 5 degrees or less.
- According to the lighting device of the present invention, the characteristic of increasing the emitted light intensity sharply with increasing light emission angle is obtained, which makes it possible to illuminate a larger area with a nearly uniform illuminance. Therefore, when the lighting device of the present invention is used in a backlight of a liquid crystal display it is expected to contribute to a reduction in the thickness of the display.
-
FIG. 1 is a cross-sectional view of a lighting device according to one embodiment of the present invention. -
FIG. 2 is a graph showing the light distribution characteristics of the lighting device ofFIG. 1 . -
FIG. 3 is a graph showing the illuminance distribution obtained when a Lambertian light source is used. -
FIG. 4 is a graph showing a condition for illuminating a flat surface with a uniform illuminance by using a single light source. - Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
-
FIG. 1 is a cross-sectional view of a lighting device (surface illumination device) according to one embodiment of the present invention. This lighting device includes a mountingsubstrate 1, aLED element 2 mounted on the mountingsubstrate 1, and alens 4 disposed on the mountingsubstrate 1 so as to cover theLED element 2. - In the present embodiment, a blue LED chip is used as the
LED element 2. Aphosphor layer 3 for converting blue light into yellow light is provided around theLED element 2 so as to encompass theLED element 2 from the side opposite to the mountingsubstrate 1. - Furthermore, in the present embodiment, the
LED element 2 and thephosphor layer 3 are encapsulated with transparent resin, and this transparent resin forms alens 4. When the encapsulation with the transparent resin is performed, the surface of the transparent resin, which is to be an interface with air, is molded in a mold into a specific shape so as to form a light exit surface (light distribution control surface) 41 that is rotationally symmetric with respect to the optical axis A. Examples of the transparent resin include epoxy resin, silicone resin, acrylic resin, and polycarbonate. Thelens 4 also may be formed of silicone rubber or the like. Thelight exit surface 41 of thelens 4 need not be completely rotationally symmetric, and it may be substantially rotationally symmetric. - A part of blue light emitted from the LED element (blue LED chip) 2 passes through the
phosphor layer 3 and the other part of the light is converted into yellow light by the action of the phosphor. As a result, white light is emitted from thephosphor layer 3. The white light emitted from thephosphor layer 3 enters thelens 4, is refracted at thelight exit surface 41 according to its incident angle with respect to thelight exit surface 41, and then emitted from thelight exit surface 41 in a specific direction. - The shape of the
light exit surface 41 is obtained in the following manner. First, a continuous surface represented in a specific functional form is designed so that its light distribution is approximated to a target light distribution, and then the resulting continuous surface is cut by a cylindrical surface having its center on the optical axis A (inFIG. 1 , the shape of the continuous surface to be cut is indicated by double-dashed lines). That is, thelight exit surface 41 includes a firstlight exit surface 41 a that extends from the optical axis A, and a secondlight exit surface 41 b that leads from the periphery of the firstlight exit surface 41 a to the mountingsubstrate 1 along the optical axis direction in which the optical axis A extends. The firstlight exit surface 41 a of the present embodiment has a concave around the optical axis A and a convex that extends outwardly from the concave. On the other hand, the secondlight exit surface 41 b is a cylindrical surface. A curve obtained by cutting thelight exit surface 41 by a plane including the optical axis A has, on the boundary between the firstlight exit surface 41 a and the secondlight exit surface 41 b, a change point P at which a rate of inclination decreases discontinuously. - The first
light exit surface 41 a and the secondlight exit surface 41 b need not necessarily be connected to each other to form a clear ridge line therebetween. For example, the firstlight exit surface 41 a and the secondlight exit surface 41 b may be connected to each other to form a sharp curve (for example, a curve with a curvature radius of about 1 mm) therebetween. That is, the rate of inclination from the firstlight exit surface 41 a to the secondlight exit surface 41 b has only to decrease substantially discontinuously at the change point P. - A position where the continuous surface is cut is a point of intersection of the continuous surface and a straight line extending from the light emission center of the
LED element 2 at an angle θcut with respect to the optical axis A. The above angle θcut is determined so that it coincides substantially with the emission angle θp with the maximum light intensity in the previously designed continuous surface. As stated herein, the “emission angle” is each of angles between light rays emitted from thelens 4 and the optical axis A. The “emission angle with the maximum light intensity” is an emission angle with the light highest intensity, among emission angles, when light rays emitted from the continuous surface are sorted by respective emission angles. - As a result of cutting the continuous surface as described above, an angle between the optical axis A and a line segment connecting the change point P and the light emission center of the
LED element 2 becomes equal to the above angle θcut. Since this angle θcut is substantially equal to the above angle θp, the angle θcut also is approximately equal to the emission angle with the highest light intensity, among emission angles, when light rays emitted from thelight exit surface 41 are sorted by respective emission angles. -
FIG. 2 is a graph showing the light distribution characteristics obtained by the previously designed continuous surface shape, and the light distribution characteristics obtained by the final shape formed by cutting the continuous surface by the cylindrical surface, that is, the light distribution characteristics of the lighting device of the present embodiment. InFIG. 2 , the horizontal axis indicates the emission angles of light rays emitted from the lighting device, and the vertical axis indicates the relative light intensities obtained by normalizing the intensities of the light rays emitted in these angle directions with respect to the intensity in the optical axis direction. - As is apparent from
FIG. 2 , the final shape formed by cutting the continuous surface by the cylindrical surface exhibits the following light distribution characteristics, compared with the previously designed continuous surface shape. That is, the peak intensity in the θp direction increases, and the emitted light intensity also increases sharply with an increase in the emission angle near the angle of θp. Thus, the resulting curve approaches more closely the curve of the uniform illumination condition of Cos−3(θ). - This is because the light rays incident on the cut cylindrical surface (second
light exit surface 41 b) are refracted in and around the θp direction as shown by dotted lines inFIG. 1 , which increases the luminous flux density in and around the θp direction. That is, light rays having the emission angle of θp include not only a light ray emitted from the firstlight exit surface 41 a but also a light ray emitted from the secondlight exit surface 41 b. - In the above example, the second
light exit surface 41 b, which is a cylindrical surface, is formed by cutting a continuous surface with a cylindrical surface having its center on the optical axis A. The effect of increasing the peak light intensity in the θp direction can be expected as long as thelight exit surface 41 has a shape capable of decreasing the rate of inclination discontinuously at a position in or around the θp direction from the light emission center of theLED element 2. For example, the secondlight exit surface 41 b may be a tapered surface extending radially toward the mountingsubstrate 1. In the case where the secondlight exit surface 41 b is a tapered surface, it is preferable that the angle with respect to the optical axis A be, for example, 10 degrees or less so that the secondlight exit surface 41 b leads from the periphery of the firstlight exit surface 41 a to the mountingsubstrate 1 along the optical axis direction. - In the above example, white light is obtained using a blue LED and a phosphor; but the present invention is not limited to this configuration. For example, it also is possible to obtain a white light source by placing LEDs of three primary colors, red, green, and blue, closely to one another near the optical axis and forming a lens to cover these LEDs. A white surface light source may be obtained by preparing a plurality of single color light sources, each including a red, green or blue LED and a lens that covers the LED, are placed in a plane so that light rays from the light sources are mixed on a surface to be illuminated.
- Such a configuration makes it possible to obtain easily the characteristic of increasing the emitted light intensity sharply with increasing light emission angle.
- The present invention makes it possible to illuminate a larger area of a target surface almost uniformly. Accordingly, when the present invention is used as a light source for backlights of liquid crystal displays, the thickness of the resulting device can be reduced and uneven illumination also can be reduced.
- The invention may be embodied in other forms without departing from the spirit or essential characteristics thereof. The embodiments disclosed in this specification are to be considered in all respects as illustrative and not limiting. The scope of the invention is indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.
Claims (3)
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JP2009-091001 | 2009-04-03 | ||
JP2009091001A JP5325639B2 (en) | 2009-04-03 | 2009-04-03 | Light emitting device |
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US20100254145A1 true US20100254145A1 (en) | 2010-10-07 |
US8147100B2 US8147100B2 (en) | 2012-04-03 |
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US12/753,307 Active 2030-06-03 US8147100B2 (en) | 2009-04-03 | 2010-04-02 | Lighting device |
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Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070187705A1 (en) * | 2006-02-15 | 2007-08-16 | Toshiaki Tanaka | Illuminating device and liquid crystal display device using the same |
US7348723B2 (en) * | 2004-09-27 | 2008-03-25 | Enplas Corporation | Emission device, surface light source device, display and light flux control member |
US7422347B2 (en) * | 2005-03-07 | 2008-09-09 | Nichia Corporation | Planar light source and planar lighting apparatus |
US20080303757A1 (en) * | 2007-06-06 | 2008-12-11 | Sony Corporation | Light emitting device, area light source apparatus and image display apparatus |
US7474475B2 (en) * | 2005-07-26 | 2009-01-06 | Samsung Electronics Co., Ltd. | Optical lens, optical package having the same, backlight assembly having the same, display device having the same, and method thereof |
US20090032827A1 (en) * | 2007-07-30 | 2009-02-05 | Philips Lumileds Lighting Company, Llc | Concave Wide Emitting Lens for LED Useful for Backlighting |
US7572036B2 (en) * | 2004-10-18 | 2009-08-11 | Samsung Electronics Co., Ltd. | Light emitting diode and lens for the same |
US7602559B2 (en) * | 2005-04-26 | 2009-10-13 | Lg Electronics Inc. | Optical lens, light emitting device package using the optical lens, and backlight unit |
US7621657B2 (en) * | 2006-01-24 | 2009-11-24 | Enplas Corporation | Light emitting device, surface light source device, display and light flux control member |
US20100195335A1 (en) * | 2009-02-03 | 2010-08-05 | Osram Sylvania, Inc. | Beam spreading optics for light emitting diodes |
US20100238669A1 (en) * | 2007-05-21 | 2010-09-23 | Illumination Management Solutions, Inc. | LED Device for Wide Beam Generation and Method of Making the Same |
US7880188B2 (en) * | 2005-02-28 | 2011-02-01 | Osram Opto Semiconductors Gmbh | Illumination device |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0818107A (en) * | 1994-06-30 | 1996-01-19 | Iwasaki Electric Co Ltd | Light emitting diode |
JP4239565B2 (en) * | 2002-03-20 | 2009-03-18 | 豊田合成株式会社 | Light emitters and lights |
JP3813509B2 (en) * | 2001-12-28 | 2006-08-23 | 株式会社東芝 | Lens-integrated light emitting device and aviation obstacle light |
JP4899502B2 (en) * | 2005-03-07 | 2012-03-21 | 日亜化学工業株式会社 | Surface irradiation light source and surface irradiation device |
JP4724618B2 (en) * | 2005-11-11 | 2011-07-13 | 株式会社 日立ディスプレイズ | LIGHTING DEVICE AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME |
-
2009
- 2009-04-03 JP JP2009091001A patent/JP5325639B2/en not_active Expired - Fee Related
-
2010
- 2010-04-02 US US12/753,307 patent/US8147100B2/en active Active
Patent Citations (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7348723B2 (en) * | 2004-09-27 | 2008-03-25 | Enplas Corporation | Emission device, surface light source device, display and light flux control member |
US7572036B2 (en) * | 2004-10-18 | 2009-08-11 | Samsung Electronics Co., Ltd. | Light emitting diode and lens for the same |
US7880188B2 (en) * | 2005-02-28 | 2011-02-01 | Osram Opto Semiconductors Gmbh | Illumination device |
US7422347B2 (en) * | 2005-03-07 | 2008-09-09 | Nichia Corporation | Planar light source and planar lighting apparatus |
US7602559B2 (en) * | 2005-04-26 | 2009-10-13 | Lg Electronics Inc. | Optical lens, light emitting device package using the optical lens, and backlight unit |
US7474475B2 (en) * | 2005-07-26 | 2009-01-06 | Samsung Electronics Co., Ltd. | Optical lens, optical package having the same, backlight assembly having the same, display device having the same, and method thereof |
US7621657B2 (en) * | 2006-01-24 | 2009-11-24 | Enplas Corporation | Light emitting device, surface light source device, display and light flux control member |
US20070187705A1 (en) * | 2006-02-15 | 2007-08-16 | Toshiaki Tanaka | Illuminating device and liquid crystal display device using the same |
US20100238669A1 (en) * | 2007-05-21 | 2010-09-23 | Illumination Management Solutions, Inc. | LED Device for Wide Beam Generation and Method of Making the Same |
US20080303757A1 (en) * | 2007-06-06 | 2008-12-11 | Sony Corporation | Light emitting device, area light source apparatus and image display apparatus |
US20090032827A1 (en) * | 2007-07-30 | 2009-02-05 | Philips Lumileds Lighting Company, Llc | Concave Wide Emitting Lens for LED Useful for Backlighting |
US20100195335A1 (en) * | 2009-02-03 | 2010-08-05 | Osram Sylvania, Inc. | Beam spreading optics for light emitting diodes |
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TWI452360B (en) * | 2010-12-10 | 2014-09-11 | Ind Tech Res Inst | Collimating optical element, collimating optical assembly, collimating optical array and collimating optical module |
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US20130076223A1 (en) * | 2011-09-28 | 2013-03-28 | Beat-Sonic Co., Ltd. | Led lamp |
CN103032728A (en) * | 2011-09-28 | 2013-04-10 | 比特硕尼克株式会社 | Led lamp |
US20140328062A1 (en) * | 2011-12-20 | 2014-11-06 | Nalux Co., Ltd. | Optical element, illumination device including the optical element, and illumination module including the illumination device |
US9857051B2 (en) * | 2011-12-20 | 2018-01-02 | Nalux Co., Ltd. | Optical element, illumination device including the optical element, and illumination module including the illumination device |
US9423117B2 (en) | 2011-12-30 | 2016-08-23 | Cree, Inc. | LED fixture with heat pipe |
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US10544925B2 (en) | 2012-01-06 | 2020-01-28 | Ideal Industries Lighting Llc | Mounting system for retrofit light installation into existing light fixtures |
US20140376217A1 (en) * | 2012-01-19 | 2014-12-25 | Enplas Corporation | Illumination device |
US9777897B2 (en) | 2012-02-07 | 2017-10-03 | Cree, Inc. | Multiple panel troffer-style fixture |
US8905575B2 (en) | 2012-02-09 | 2014-12-09 | Cree, Inc. | Troffer-style lighting fixture with specular reflector |
US10514139B2 (en) | 2012-03-23 | 2019-12-24 | Ideal Industries, Llc | LED fixture with integrated driver circuitry |
US9310038B2 (en) | 2012-03-23 | 2016-04-12 | Cree, Inc. | LED fixture with integrated driver circuitry |
US9494294B2 (en) | 2012-03-23 | 2016-11-15 | Cree, Inc. | Modular indirect troffer |
US10054274B2 (en) | 2012-03-23 | 2018-08-21 | Cree, Inc. | Direct attach ceiling-mounted solid state downlights |
US9360185B2 (en) | 2012-04-09 | 2016-06-07 | Cree, Inc. | Variable beam angle directional lighting fixture assembly |
US9874322B2 (en) | 2012-04-10 | 2018-01-23 | Cree, Inc. | Lensed troffer-style light fixture |
US9285099B2 (en) | 2012-04-23 | 2016-03-15 | Cree, Inc. | Parabolic troffer-style light fixture |
US20150123938A1 (en) * | 2012-07-06 | 2015-05-07 | Freescale Semiconductor, Inc. | Electronic device for proximity detection, a light emitting diode for such electronic device, a control unit for such electronic device, an apparatus comprising such electronic device and an associated method |
US8931929B2 (en) | 2012-07-09 | 2015-01-13 | Cree, Inc. | Light emitting diode primary optic for beam shaping |
WO2014011469A1 (en) * | 2012-07-09 | 2014-01-16 | Cree, Inc. | Light emitting diode primary optic for beam shaping |
CN102818218A (en) * | 2012-09-11 | 2012-12-12 | 创高国际企业有限公司 | Secondary optical lens, light-emitting device and guardrail lamp |
CN103775966A (en) * | 2012-10-23 | 2014-05-07 | 鸿富锦精密工业(深圳)有限公司 | Lens and light source module with same |
US9494304B2 (en) | 2012-11-08 | 2016-11-15 | Cree, Inc. | Recessed light fixture retrofit kit |
US10309627B2 (en) | 2012-11-08 | 2019-06-04 | Cree, Inc. | Light fixture retrofit kit with integrated light bar |
US10648643B2 (en) | 2013-03-14 | 2020-05-12 | Ideal Industries Lighting Llc | Door frame troffer |
US9423104B2 (en) | 2013-03-14 | 2016-08-23 | Cree, Inc. | Linear solid state lighting fixture with asymmetric light distribution |
US10228111B2 (en) | 2013-03-15 | 2019-03-12 | Cree, Inc. | Standardized troffer fixture |
US9052075B2 (en) | 2013-03-15 | 2015-06-09 | Cree, Inc. | Standardized troffer fixture |
CN104421833A (en) * | 2013-08-22 | 2015-03-18 | 鸿富锦精密工业(深圳)有限公司 | Lens and light source module comprising same |
US20150055352A1 (en) * | 2013-08-22 | 2015-02-26 | Hon Hai Precision Industry Co., Ltd. | Optical lens and light source module having the same |
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US10012354B2 (en) | 2015-06-26 | 2018-07-03 | Cree, Inc. | Adjustable retrofit LED troffer |
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US8147100B2 (en) | 2012-04-03 |
JP2010244790A (en) | 2010-10-28 |
JP5325639B2 (en) | 2013-10-23 |
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